/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "fuse_i.h"
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/kernel.h>
static struct file_operations fuse_direct_io_file_operations;
static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
struct fuse_open_out *outargp)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_open_in inarg;
struct fuse_req *req;
int err;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
memset(&inarg, 0, sizeof(inarg));
inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->out.numargs = 1;
req->out.args[0].size = sizeof(*outargp);
req->out.args[0].value = outargp;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
return err;
}
struct fuse_file *fuse_file_alloc(void)
{
struct fuse_file *ff;
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
if (ff) {
ff->release_req = fuse_request_alloc();
if (!ff->release_req) {
kfree(ff);
ff = NULL;
}
}
return ff;
}
void fuse_file_free(struct fuse_file *ff)
{
fuse_request_free(ff->release_req);
kfree(ff);
}
void fuse_finish_open(struct inode *inode, struct file *file,
struct fuse_file *ff, struct fuse_open_out *outarg)
{
if (outarg->open_flags & FOPEN_DIRECT_IO)
file->f_op = &fuse_direct_io_file_operations;
if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
invalidate_inode_pages(inode->i_mapping);
ff->fh = outarg->fh;
file->private_data = ff;
}
int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
struct fuse_open_out outarg;
struct fuse_file *ff;
int err;
/* VFS checks this, but only _after_ ->open() */
if (file->f_flags & O_DIRECT)
return -EINVAL;
err = generic_file_open(inode, file);
if (err)
return err;
/* If opening the root node, no lookup has been performed on
it, so the attributes must be refreshed */
if (get_node_id(inode) == FUSE_ROOT_ID) {
err = fuse_do_getattr(inode);
if (err)
return err;
}
ff = fuse_file_alloc();
if (!ff)
return -ENOMEM;
err = fuse_send_open(inode, file, isdir, &outarg);
if (err)
fuse_file_free(ff);
else {
if (isdir)
outarg.open_flags &= ~FOPEN_DIRECT_IO;
fuse_finish_open(inode, file, ff, &outarg);
}
return err;
}
/* Special case for failed iget in CREATE */
static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
{
/* If called from end_io_requests(), req has more than one
reference and fuse_reset_request() cannot work */
if (fc->connected) {
u64 nodeid = req->in.h.nodeid;
fuse_reset_request(req);
fuse_send_forget(fc, req, nodeid, 1);
} else
fuse_put_request(fc, req);
}
void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
u64 nodeid, struct inode *inode, int flags, int isdir)
{
struct fuse_req * req = ff->release_req;
struct fuse_release_in *inarg = &req->misc.release_in;
inarg->fh = ff->fh;
inarg->flags = flags;
req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
req->in.h.nodeid = nodeid;
req->inode = inode;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_release_in);
req->in.args[0].value = inarg;
request_send_background(fc, req);
if (!inode)
req->end = fuse_release_end;
kfree(ff);
}
int fuse_release_common(struct inode *inode, struct file *file, int isdir)
{
struct fuse_file *ff = file->private_data;
if (ff) {
struct fuse_conn *fc = get_fuse_conn(inode);
u64 nodeid = get_node_id(inode);
fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
}
/* Return value is ignored by VFS */
return 0;
}
static int fuse_open(struct inode *inode, struct file *file)
{
return fuse_open_common(inode, file, 0);
}
static int fuse_release(struct inode *inode, struct file *file)
{
return fuse_release_common(inode, file, 0);
}
static int fuse_flush(struct file *file)
{
struct inode *inode = file->f_dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_file *ff = file->private_data;
struct fuse_req *req;
struct fuse_flush_in inarg;
int err;
if (is_bad_inode(inode))
return -EIO;
if (fc->no_flush)
return 0;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
req->in.h.opcode = FUSE_FLUSH;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->file = file;
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
if (err == -ENOSYS) {
fc->no_flush = 1;
err = 0;
}
return err;
}
int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
int isdir)
{
struct inode *inode = de->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_file *ff = file->private_data;
struct fuse_req *req;
struct fuse_fsync_in inarg;
int err;
if (is_bad_inode(inode))
return -EIO;
if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
return 0;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
inarg.fsync_flags = datasync ? 1 : 0;
req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->file = file;
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
if (err == -ENOSYS) {
if (isdir)
fc->no_fsyncdir = 1;
else
fc->no_fsync = 1;
err = 0;
}
return err;
}
static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
{
return fuse_fsync_common(file, de, datasync, 0);
}
void fuse_read_fill(struct fuse_req *req, struct file *file,
struct inode *inode, loff_t pos, size_t count, int opcode)
{
struct fuse_file *ff = file->private_data;
struct fuse_read_in *inarg = &req->misc.read_in;
inarg->fh = ff->fh;
inarg->offset = pos;
inarg->size = count;
req->in.h.opcode = opcode;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->file = file;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_read_in);
req->in.args[0].value = inarg;
req->out.argpages = 1;
req->out.argvar = 1;
req->out.numargs = 1;
req->out.args[0].size = count;
}
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
struct inode *inode, loff_t pos, size_t count)
{
struct fuse_conn *fc = get_fuse_conn(inode);
fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
request_send(fc, req);
return req->out.args[0].size;
}
static int fuse_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req;
int err;
err = -EIO;
if (is_bad_inode(inode))
goto out;
err = -EINTR;
req = fuse_get_request(fc);
if (!req)
goto out;
req->out.page_zeroing = 1;
req->num_pages = 1;
req->pages[0] = page;
fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err)
SetPageUptodate(page);
fuse_invalidate_attr(inode); /* atime changed */
out:
unlock_page(page);
return err;
}
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
{
int i;
fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
for (i = 0; i < req->num_pages; i++) {
struct page *page = req->pages[i];
if (!req->out.h.error)
SetPageUptodate(page);
else
SetPageError(page);
unlock_page(page);
}
fuse_put_request(fc, req);
}
static void fuse_send_readpages(struct fuse_req *req, struct file *file,
struct inode *inode)
{
struct fuse_conn *fc = get_fuse_conn(inode);
loff_t pos = page_offset(req->pages[0]);
size_t count = req->num_pages << PAGE_CACHE_SHIFT;
req->out.page_zeroing = 1;
fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
if (fc->async_read) {
req->end = fuse_readpages_end;
request_send_background(fc, req);
} else {
request_send(fc, req);
fuse_readpages_end(fc, req);
}
}
struct fuse_readpages_data {
struct fuse_req *req;
struct file *file;
struct inode *inode;
};
static int fuse_readpages_fill(void *_data, struct page *page)
{
struct fuse_readpages_data *data = _data;
struct fuse_req *req = data->req;
struct inode *inode = data->inode;
struct fuse_conn *fc = get_fuse_conn(inode);
if (req->num_pages &&
(req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
req->pages[req->num_pages - 1]->index + 1 != page->index)) {
fuse_send_readpages(req, data->file, inode);
data->req = req = fuse_get_request(fc);
if (!req) {
unlock_page(page);
return -EINTR;
}
}
req->pages[req->num_pages] = page;
req->num_pages ++;
return 0;
}
static int fuse_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct inode *inode = mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_readpages_data data;
int err;
if (is_bad_inode(inode))
return -EIO;
data.file = file;
data.inode = inode;
data.req = fuse_get_request(fc);
if (!data.req)
return -EINTR;
err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
if (!err) {
if (data.req->num_pages)
fuse_send_readpages(data.req, file, inode);
else
fuse_put_request(fc, data.req);
}
return err;
}
static size_t fuse_send_write(struct fuse_req *req, struct file *file,
struct inode *inode, loff_t pos, size_t count)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_file *ff = file->private_data;
struct fuse_write_in inarg;
struct fuse_write_out outarg;
memset(&inarg, 0, sizeof(struct fuse_write_in));
inarg.fh = ff->fh;
inarg.offset = pos;
inarg.size = count;
req->in.h.opcode = FUSE_WRITE;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->file = file;
req->in.argpages = 1;
req->in.numargs = 2;
req->in.args[0].size = sizeof(struct fuse_write_in);
req->in.args[0].value = &inarg;
req->in.args[1].size = count;
req->out.numargs = 1;
req->out.args[0].size = sizeof(struct fuse_write_out);
req->out.args[0].value = &outarg;
request_send(fc, req);
return outarg.size;
}
static int fuse_prepare_write(struct file *file, struct page *page,
unsigned offset, unsigned to)
{
/* No op */
return 0;
}
static int fuse_commit_write(struct file *file, struct page *page,
unsigned offset, unsigned to)
{
int err;
size_t nres;
unsigned count = to - offset;
struct inode *inode = page->mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
loff_t pos = page_offset(page) + offset;
struct fuse_req *req;
if (is_bad_inode(inode))
return -EIO;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
req->num_pages = 1;
req->pages[0] = page;
req->page_offset = offset;
nres = fuse_send_write(req, file, inode, pos, count);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err && nres != count)
err = -EIO;
if (!err) {
pos += count;
spin_lock(&fuse_lock);
if (pos > inode->i_size)
i_size_write(inode, pos);
spin_unlock(&fuse_lock);
if (offset == 0 && to == PAGE_CACHE_SIZE) {
clear_page_dirty(page);
SetPageUptodate(page);
}
}
fuse_invalidate_attr(inode);
return err;
}
static void fuse_release_user_pages(struct fuse_req *req, int write)
{
unsigned i;
for (i = 0; i < req->num_pages; i++) {
struct page *page = req->pages[i];
if (write)
set_page_dirty_lock(page);
put_page(page);
}
}
static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
unsigned nbytes, int write)
{
unsigned long user_addr = (unsigned long) buf;
unsigned offset = user_addr & ~PAGE_MASK;
int npages;
/* This doesn't work with nfsd */
if (!current->mm)
return -EPERM;
nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
down_read(¤t->mm->mmap_sem);
npages = get_user_pages(current, current->mm, user_addr, npages, write,
0, req->pages, NULL);
up_read(¤t->mm->mmap_sem);
if (npages < 0)
return npages;
req->num_pages = npages;
req->page_offset = offset;
return 0;
}
static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
size_t count, loff_t *ppos, int write)
{
struct inode *inode = file->f_dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
size_t nmax = write ? fc->max_write : fc->max_read;
loff_t pos = *ppos;
ssize_t res = 0;
struct fuse_req *req;
if (is_bad_inode(inode))
return -EIO;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
while (count) {
size_t nres;
size_t nbytes = min(count, nmax);
int err = fuse_get_user_pages(req, buf, nbytes, !write);
if (err) {
res = err;
break;
}
nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
nbytes = min(count, nbytes);
if (write)
nres = fuse_send_write(req, file, inode, pos, nbytes);
else
nres = fuse_send_read(req, file, inode, pos, nbytes);
fuse_release_user_pages(req, !write);
if (req->out.h.error) {
if (!res)
res = req->out.h.error;
break;
} else if (nres > nbytes) {
res = -EIO;
break;
}
count -= nres;
res += nres;
pos += nres;
buf += nres;
if (nres != nbytes)
break;
if (count)
fuse_reset_request(req);
}
fuse_put_request(fc, req);
if (res > 0) {
if (write) {
spin_lock(&fuse_lock);
if (pos > inode->i_size)
i_size_write(inode, pos);
spin_unlock(&fuse_lock);
}
*ppos = pos;
}
fuse_invalidate_attr(inode);
return res;
}
static ssize_t fuse_direct_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return fuse_direct_io(file, buf, count, ppos, 0);
}
static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct inode *inode = file->f_dentry->d_inode;
ssize_t res;
/* Don't allow parallel writes to the same file */
mutex_lock(&inode->i_mutex);
res = fuse_direct_io(file, buf, count, ppos, 1);
mutex_unlock(&inode->i_mutex);
return res;
}
static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
if ((vma->vm_flags & VM_SHARED)) {
if ((vma->vm_flags & VM_WRITE))
return -ENODEV;
else
vma->vm_flags &= ~VM_MAYWRITE;
}
return generic_file_mmap(file, vma);
}
static int fuse_set_page_dirty(struct page *page)
{
printk("fuse_set_page_dirty: should not happen\n");
dump_stack();
return 0;
}
static struct file_operations fuse_file_operations = {
.llseek = generic_file_llseek,
.read = generic_file_read,
.write = generic_file_write,
.mmap = fuse_file_mmap,
.open = fuse_open,
.flush = fuse_flush,
.release = fuse_release,
.fsync = fuse_fsync,
.sendfile = generic_file_sendfile,
};
static struct file_operations fuse_direct_io_file_operations = {
.llseek = generic_file_llseek,
.read = fuse_direct_read,
.write = fuse_direct_write,
.open = fuse_open,
.flush = fuse_flush,
.release = fuse_release,
.fsync = fuse_fsync,
/* no mmap and sendfile */
};
static struct address_space_operations fuse_file_aops = {
.readpage = fuse_readpage,
.prepare_write = fuse_prepare_write,
.commit_write = fuse_commit_write,
.readpages = fuse_readpages,
.set_page_dirty = fuse_set_page_dirty,
};
void fuse_init_file_inode(struct inode *inode)
{
inode->i_fop = &fuse_file_operations;
inode->i_data.a_ops = &fuse_file_aops;
}